基于四分之一波片-复合双折射光楔-偏振片的空间偏振调制结构, 提出了四光束校正方法, 对四分之一波片延迟量误差进行校正, 从而达到提高线偏振测量精度的目的; 利用计算机仿真手段, 研究了待测目标圆偏振参量变化时, 线偏振参量测量结果的变化情况以及相应的测量精度水平。仿真结果表明: 当待测目标的线偏振度、圆偏振度分别在0.1~0.2、0~0.2随机波动时, 延迟校正后的斯托克斯参量Qi、Ui以及线偏振度的测量精度优于10-3, Ui以及线偏振度的测量精度比延迟校正前提高了约14倍。

In order to insure the accuracy in linear polarimetry, a four-beam method was presented to calibrate the retardance of quarter wave plate. The method was based on spatial modulating optical structure, which was composed of quarter wave plate, combo birefringent wedge and polarizer. Variety of polarization measurement and polarization measuring accuracy was researched by simulation approach, when degree of circular polarization of target was changed. It was indicated that the measuring accuracy of Qi, Ui and degree of linear polarization were better than 10-3 with retardance calibration, when degree of linear and circular polarization is randomize between 0.1 to 0.2 and 0 to 0.2 respectively. Accuracy of polarization parameter measuring, except Qi, is about 14 times higher than those without retardance calibrating process.